It was the first time the high school freshman had used that particular tone, but he continued to deploy it as he menaced his mom and dad.

“He used the kind of language of abusive husbands — manipulating and controlling,” says Quillan, who had installed locks on every door in her house except her son’s bedroom. “I was terrified of what he was going to do next.”

The boy — whom Quillan chooses to call Kevin in her interview with The Post in reference to the unnerving Lionel Shriver novel “We Need To Talk About Kevin” about a school shooter in upstate New York — was out of control.

After years of cruel and violent behavior plus multiple suspensions and expulsions from school, psychiatrists finally diagnosed the then-14-year-old Kevin with “conduct disorder,” which, in its most extreme form, can be a precursor to psychopathy.

Psychopathy, which is often used interchangeably with the term sociopathy, is believed to affect 1 percent of adults. Key attributes that sociopaths and psychopaths have in common include a disregard for laws, social mores and the rights of others, a failure to feel remorse or guilt and, in some but not all cases, a tendency to violence.

The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) dictates that people under the age of 18 cannot be labelled psychopaths. However, in 2013 the American Psychiatric Association decided to include the condition “conduct disorder with callous and unemotional traits” for children ages 12 and over.

According to a 2001 report published in the journal American Family Physician, approximately 6 to 16 percent of boys and 2 to 9 percent of girls meet the diagnostic criteria for conduct disorder — only a fraction of which have the “callous and unemotional” label that can potentially lead to psychopathy in adulthood.

More than 50 studies have found that kids with the latter diagnosis are more likely to become criminals or display aggressive, psychopathic traits later in life. It has been reported that Nikolas Cruz, the 19-year-old who allegedly shot and killed 17 people at Marjory Stoneman Douglas High School in Parkland, Fla., last month showed classic signs of the disorder as a child, including abusing animals.

“Psychopaths don’t just appear when they are 20. They are always different from an early age,” Kent Kiehl, a psychology professor at the University of New Mexico and the author of “The Psychopath Whisperer,” tells The Post.

Characteristics to look for — as detailed in the widely used Hare Psychopathy Checklist Youth Version considered by clinicians and researchers to be the “gold standard” in assessing psychopathy — include lack of empathy, lack of guilt and regret, pathological lying, grandiose self-worth and failure to accept responsibility for actions such as fighting and bullying.

“Individuals who score high on those traits are more likely to produce further violence,” adds Kiehl. “If they are sanctioned but continue on the same path, it’s not a perfect indicator, but it’s enough to cause concern.”

Kiehl notes that research has shown that psychopathy is hereditary roughly half of the time. But his own breakthrough was the discovery that the psychopathic brain has a different structure than a “normal” one.

In 2014, he conducted a major study that found at least two abnormalities in the brains of adult psychopaths. There was a lack of gray matter in the section involved in processing emotions, while the area that reacts to excitement and thrills is overactive. Although the research has not been carried out yet, the pattern is likely to also occur in the brains of “callous and unemotional” children. “Brain science has helped us understand what is different about these kids,” adds Kiehl.

At the moment, there is no such thing as a “cure” for psychopathy or conduct disorder. But early intervention can be key for harm reduction, even with children as young as 2 or 3.

Paul Frick, a psychology professor at Louisiana State University and the author of “Conduct Disorder and Severe Antisocial Behavior,” recommends a range of therapies, most of which revolve around rewards systems rather than punishments.

“There are so-called ‘emotion coaching’ techniques that parents and therapists can employ to help children pay attention to the feelings of others,” he explains. “We find that they miss the cues that another child is upset.

“By saying: ‘Can you see how Johnny is feeling?’ [when a toy is snatched from him] and getting them to respond correctly, you can motivate them. You give them a star or a sticker as an incentive.

“Even though it doesn’t come naturally to them, they can learn others’ perspectives.”

Experts can identify a callous and unemotional child when they are as young as 3 or 4. Faced with a crying peer, typically developing children either try to comfort them or take flight. But those with the mental condition remain in place, showing apathy and coldness.

Remarkably, the psychology department at King’s College London has been able to trace the characteristics back to infancy. They tested more than 200 babies at 5 months old, tracking whether they preferred looking at a person’s face or at a red ball. The tots who favored the ball displayed more callous traits two and a half years later.

For Quillan, hindsight is 20/20, but she distinctly recalls the first signs that Kevin had behavioral issues at the age of just 8 months.

“He had teeth and would bite me while he was breast-feeding and he would laugh. He thought it was hilarious. I tried looking very sad and mimicking crying to show it was hurting me, but he would only laugh,” says Quillan, who ended up having to put him on formula.

“It didn’t occur to me until much later that this was a child for whom the amusement of my reaction when he bit me was a greater reward than food.”

Now 18, Kevin, who has had numerous run-ins with police, including for shoplifting, was made a ward of state and no longer lives with his parents. He lives in a residential school for “at-risk” youth in California, where he is on a waiting list to receive treatment, such as therapy, to build empathy.

“Because there is no real treatment for conduct disorder. All you can do is wait for your child to be arrested and enter the juvenile system and hope they get better,” says his 40-year-old homemaker mom.

“Luckily, Kevin is no longer violent and is actually cooperative.”

He is doing so well that he is about to receive his high school diploma, recently won an award for wrestling and has encouraged his mother to tell his story.

Now Quillian, who has no other kids, is focusing on advocacy and encouraging parents facing similar nightmares to hers. Three years ago, she formed a support group for families with kids with CD that has 420 members worldwide. More recently, she launched the Society for Treatment Options for Potential Psychopaths to bring awareness and to campaign for treatment for these children before they cause serious harm.

Adds Quillan: “As every news article came out about Parkland and Nikolas Cruz, I thought: ‘My God, this could easily be one of our kids.’”

A strong focus on reward combined with a lack of self-control appears to be linked to the tendency to commit an offence. Brain scans show that this combination occurs in psychopathic criminals, say researchers from Nijmegen in an article in the journal Social Cognitive and Affective Neuroscience.

any criminal offenders display psychopathic traits, such as antisocial and impulsive behaviour. And yet some individuals with psychopathic traits do not commit offences for which they are convicted. As with any other form of behaviour, psychopathic behaviour has a neurobiological basis.

Researchers from the Donders Institute and the Department of Psychiatry at Radboudumc wanted to find out whether the way a psychopath’s brain works is visibly different from that of a non-psychopath. And whether there are differences between the brains of criminal and non-criminal psychopaths.

Reward center more strongly activated

Dirk Geurts, researcher in the Department of Psychiatry at Radboudumc: “We carried out tests on 14 convicted psychopathic individuals, and 20 non-criminal individuals, half of whom had a high score on the psychopathy scale. The participants performed tests while their brain activity was measured in an MRI scanner. We saw that the reward centre in the brains of people with many psychopathic traits (both criminal and non-criminal) were more strongly activated than those in people without psychopathic traits. It has already been proved that the brains of non-criminal individuals with psychopathic traits are triggered by the expectation of reward. This research shows that this is also the case for criminal individuals with psychopathic traits.”

Little self-control and sensitivity to reward

Another interesting difference was discovered between non-criminal people with multiple psychopathic traits and criminal people with psychopathic traits.

Geurts: “There is a difference in the communication between the reward centre and an area in the middle of the forebrain. Good communication between these areas would appear to be a condition for self-control. Our results seem to indicate that the tendency to commit an offence arises from a combination of a strong focus on reward and a lack of self-control. This is the first research project in which convicted criminals were actually examined.”

Predictors of criminal behaviour

Psychopathy consists of several elements. On the one hand, there is a lack of empathy and emotional involvement. On the other hand, we see impulsive and seriously antisocial, egocentric behaviour.

Professor of Psychiatry and coordinator of the research Robbert-Jan Verkes: “Especially the latter character traits seem to be connected with an excessively sensitive reward centre. The presence of these impulsive and antisocial traits predict criminal behaviour more accurately than a lack of empathy. The next relevant question would be: what causes these brain abnormalities? It is probably partly hereditary, but abuse and severe stress during formative years also play a significant role. Follow-up studies will provide more information.

Brain scans in courtrooms?

So what do these findings mean for the free will? If the brain plays such an important role, to what extent can an individual be held responsible for his/her crimes? Will we be seeing brain scans in the courtroom?

Verkes: “For the time being, these findings are only important at group level as they concern variations within the range of normal results. Of course if we can refine these and other types of examinations, we may well see brain scans being used in forensic psychiatric examinations of diminished responsibility in the future.”

A former University of Colorado professor has been arrested on suspicion of creating a company to sell marked-up lab equipment to the Boulder campus in what prosecutors call a theft “scheme.”

Donald Cooper, 44, was arrested at his home in Boulder on Tuesday afternoon, according to Boulder County District Attorney’s Office officials. It was unclear late Tuesday if Cooper had posted bond, which was set at $5,000.

He is facing a felony charge of theft between $20,000 and $100,000. Prosecutors allege that he created Boulder Science Resource to buy lasers and other lab equipment that he marked up 300 percent and then resold to his university laboratory, according to an arrest affidavit.

The arrangement also benefitted the professor’s father, who received a salary and a car from Boulder Science Resource, according to the arrest affidavit.

In total, CU paid Boulder Science Resource $97,554.03 between Jan. 1, 2009, and April 30, 2013, according to the affidavit.

According to CU’s calculations, Cooper’s markups cost the university $65,036.

Cooper resigned in July 2014 as part of a settlement deal with the university, which had begun the process of firing him on suspicion of fiscal misconduct. He had been director of the molecular neurogenetics and optophysiology laboratory in CU’s Institute for Behavioral Genetics, where he was a tenured associate professor.

After he learned about the university’s internal investigation, Cooper filed a notice of claim in September 2013 seeking $20 million in damages. Any person who wishes to sue a state entity must first file a notice of claim.

Cooper’s attorney Seth Benezra wrote in the notice of claim that Gary Cooper, the professor’s father, was the sole owner of Boulder Science Resource. He also wrote that the company sold CU equipment “at prices that were greatly discounted.”

Donald Cooper also complained that CU investigators had obtained an email about his father’s “alleged mental impairment,” according to the notice of claim.

“(The investigator’s) theory is that Gary Cooper lacks the mental capacity to run (Boulder Science Resource) and so Dr. Cooper must really be in charge,” Benezra wrote. “This assertion was pure speculation based on entirely private information and was rebutted by Dr. Cooper in multiple meetings with investigators.”

Benezra did not return messages from the Daily Camera on Tuesday. It’s unclear who is representing Cooper in the criminal case.

Though Cooper claims that his father was in charge of the company, prosecutors assert that the professor “employed a scheme” to deceive the university for his own gain, according to the affidavit.

“It is alleged that (Boulder Science Resource) was created to defraud the University of Colorado Boulder by acting as a middleman to generate income to employ Gary and to provide personal benefit for Cooper,” wrote Alisha Baurer, an investigator in the District Attorney’s Office.

‘Fake business’

CU was tipped off about Boulder Science Resource by another employee in Cooper’s department, who told investigators that he heard about the arrangement from Cooper’s ex-wife, according to the arrest affidavit.

The ex-wife told the CU employee that Cooper had created a “fake business” using “dirty money” from grants and start-up funds, according to the affidavit.

The financial manager for Cooper’s department told investigators that he never mentioned that his dad owned Boulder Science Resource, and said Cooper only referred to “Gary” by his first name, according to the affidavit.

The DA’s Office determined that Gary Cooper received $23,785.80 from Boulder Science Resource in the form of a salary and a car. They also found that $31,974.89 was paid from the company’s accounts to Donald Cooper’s personal credit card and that $14,733.54 was paid to his personal PayPal account from the business, according to the affidavit.

CU’s internal audit found that Boulder Science Resource had no customers other than the university and Mobile Assay, a company founded by Donald Cooper based on a technology he developed at the university.

Some of the money CU paid to Boulder Science Resource came from federal grants, including $7,220 from the National Institutes of Health and $15,288 from the National Institute on Drug Abuse, according to the internal audit report.

CU’s investigation found that although Cooper claimed his father purchased the lab equipment for Boulder Science Resource, the professor used his university email account to negotiate with the manufacturers.

“It is internal audit’s conclusion that the forgoing acts/failures to act were done with intent to gain an unauthorized benefit,” according to the audit report.

Boulder Science Resource was dissolved in December 2013, according to the Secretary of State’s Office.

Settlement terms

Reached by phone Tuesday afternoon, Patrick O’Rourke, CU’s chief legal officer, said the university was aware of Cooper’s arrest and will cooperate with prosecutors.

CU settled with Cooper last summer after initiating termination proceedings. In exchange for his resignation, the university agreed to provide the professor with a letter of reference “acknowledging his significant achievement in creating a neuroscience undergraduate program,” according to the settlement document.

CU also paid $20,000 to partially reimburse Cooper’s attorney and forgave an $80,000 home loan. CU provides down payment-assistance loans to some faculty members.

Had the university continued the termination process, which is lengthy, Cooper would have continued to receive his full salary of $89,743 and all benefits during the proceedings.

O’Rourke said the university instead opted to accept Cooper’s resignation and saved money with the settlement.

Men who post selfies on social media such as Instagram and Facebook have higher than average traits of narcissism and psychopathy, according to a new study from academics at Ohio State University.

Furthermore, people who use filters to edit shots score even higher for anti-social behaviour such as narcissism, an obsession with one’s own appearance.

Psychologists from the University of Ohio sampled 800 men aged 18 to 40 about their photo-posting habits on social media.

As well as questionnaires to test their levels of vanity, they were also asked if they edited their photos by cropping them or adding a filter.

Assistant Professor Jesse Fox, lead author of the study at The Ohio State University, said: ‘It’s not surprising that men who post a lot of selfies and spend more time editing them are more narcissistic, but this is the first time it has actually been confirmed in a study.

‘The more interesting finding is that they also score higher on this other anti-social personality trait, psychopathy, and are more prone to self-objectification” she said.